Choroidal vascularity index changes in proliferative and nonproliferative macular telangiectasia type 2

Abstract: PURPOSE: This study aimed to evaluate the choroidal vascularity index (CVI) in patients with nonproliferative and proliferative macular telangiectasia type 2 (MacTel-2) compared to healthy controls, assess the impact of ellipsoid zone (EZ) disruption on CVI, and determine whether CVI measurements vary with different binarization areas. MATERIALS AND METHODS: CVIs from MacTel-2 eyes were compared to those of healthy controls. MacTel-2 eyes were categorized as proliferative or nonproliferative and further subdivided by the presence or absence of EZ disruption. CVI was measured in three regions: 1500 μm, 4000 μm, and the total macular choroidal area (TCA). Statistical analyses included paired samples t -tests, independent samples t -tests, and Mann–Whitney U -tests. P < 0.05 was considered statistically significant. RESULTS: This study included 90 eyes each from MacTel-2 patients and healthy controls. CVIs did not significantly differ between eyes with and without EZ disruption in either MacTel-2 group ( P > 0.05). CVIs beneath EZ-disrupted areas were also comparable to intact zones ( P > 0.05). No significant CVI difference was observed between nonproliferative and proliferative MacTel-2 eyes ( P > 0.1). However, both the groups had significantly lower CVIs than healthy controls across all measured areas ( P < 0.001 for nonproliferative and P < 0.05 for proliferative). CVI values were consistent across all binarization areas ( P > 0.1). CONCLUSION: EZ disruption does not affect CVI. CVIs were similar in nonproliferative and proliferative MacTel-2, both lower than in healthy eyes. CVI also remained consistent across different binarization areas, confirming its reliability regardless of area size.